1. Field of the Invention
The Present invention relates to a method of producing a chip type LC composite part and a chip type LC composite network part to be used as noise filters, etc.
2. Description of Related Art
For producing a chip type LC composite part, there are conventionally two methods: sheet lamination method and LC coupling method. In the sheet lamination method. a capacitor section made of a dielectric material and a coil section made of a magnetic material are laminated into an unsintered substrate, and the laminated substrate is divided into pieces each of which will be made into a product. Each of the laminated pieces is sintered, and external electrodes are formed on the sintered piece. However, since the sintering contraction rate of the dielectric material differs from that of the magnetic material, when the capacitor section and the coil section are sintered together, there is a fear that the capacitor section and the coil section may be disconnected from each other, or may have distortion and cracks. For the reasons, complicated production control has been required.
In the LC coupling method, a capacitor section and a coil section which were sintered separately are connected together by brazing or soldering, and the integrated body is subject to a molding process. The LC coupling method includes more production processes than the sheet lamination method, which results in increase in production cost.
Since the arrangement of components is more dense and wiring has a narrower pattern pitch recently, there is a growing demand for LC composite network parts which can cope with a narrower pattern pitch. However, an LC composite network part which can cope with a narrower pattern pitch has been conventionally formed of a capacitor section and a coil section. Therefore it has been required to connect the sections via a connector, and there has been a problem that a large space is required for mounting the part on a circuit board.